The purpose of this study is to evaluate the efficacy of three different surgical treatments (1. Bilateral myringotomy and tube insertion (M&T); 2. Adenoidectomy and bilateral myringotomy (A&T); 3. Adenoidectomy with myringotomy and tympanostomy tube insertion (A-M&T)) in reducing subsequent episodes of middle ear disease and hearing loss caused by the fluid in the middle ear in children aged 24-47 months. The fluid in the middle ear is of at least three months' duration and unresponsive to standardized, recent antimicrobial treatment. The children are assigned to one of the three surgical treatments. After surgery, they are followed with examinations monthly and at the time of intercurrent infections for three years.